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Psychology 304: Brain and Behaviour

Lecture 3

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Research Methods

1. What types of research methods do biological psychologists use? (continued)

2. What ethical considerations do biological psychologists face?

3. How do biological psychologists assess the structure and function of the nervous system?

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1. distinguish between the distinct types of studies used in biopsychological research.

2. discuss the ethical guidelines for conducting human and nonhuman biopsychological research.

By the end of today’s class, you should be able to:

3. describe the diverse methods used by biological psychologists to assess nervous system structure and

function.

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Example: Lester and Gorzalka (1988).

Randomly assigned female rats to one of two treatment groups:

Treatment Group A: Copulated with one male, then with a second male, and then with the original male again (i.e., 1, 2, 1).

Treatment Group B: Copulated with one male, then with a second male, and then with a third male (i.e., 1, 2, 3).

From last class ....

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05

101520253035

1st Qtr

Male 1 Male 2 Male 1

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101520253035

1st Qtr

Male 1 Male 2 Male 3

Results:

Treatment Group A Treatment Group B

Mea

n Lo

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urat

ion

(Min

utes

)

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3. Correlational studies

Designed to examine the extent to which 2 naturally-occurring variables covary.

What types of research methods do biological psychologists use? (continued)

Typically measured by the Pearson product-moment correlation coefficient (r).

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r measures the extent to which a linear relationship exists between 2 variables.

Magnitude of r: strength of relationship between variables.

Sign of r (+ vs. -): direction of relationship between variables.

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Example: Morris, Udry, Khan-Dawood, and Dawood (1987).

Examined the correlation between testosterone levels among midcycle women and frequency of sexual intercourse.

Found a positive correlation of .62 (p<.01), indicating that higher midcycle testosterone levels are associated with greater frequency of sexual intercourse.

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4. Case studies

Designed to examine a single case or subject.

An excellent source of testable hypotheses.

Example: Parkin (2003): “The case of NA and the perils of a miniature foil.”

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What ethical considerations do biological psychologists face?

• Both human and nonhuman animals are the subject of biopsychological research.

• The use of nonhuman animals in biopsychological research is based on the assumption that there is evolutionary continuity in the brain.

• The comparison of biological processes and behaviour across species is referred to as the “comparative approach.”

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• Biological psychologists confront a host of ethical considerations when conducting research with both human and nonhuman subjects.

Examples:

Drug vs. placebo administration to humans with HIV.

Cortical lesions among non-human primates.

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• Ethical guidelines for humans stress informed consent (American Psychological Association, 2008):

Coercion is not allowed (e.g., participants must be able to decline without penalty).

Participants must be given sufficient information to make an informed decision regarding participation.

Participants must be assured confidentiality.

Participants must be given the opportunity to learn the study’s outcomes.

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• Ethical guidelines for nonhumans stress need, housing, and care (American Psychological Association, 2008):

Nonhuman animal research should have a clear scientific purpose.

Excellent housing and care must be provided. Regular checkups by veterinarians and inspections must be conducted.

Procedures must cause as little pain and distress as possible.

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• Debate: The use of nonhuman subjects for studies that are not acceptable for humans continues to generate debate.

• Informative websites relevant to this debate are:

www.apa.org/science/anguide.html www.the-aps.org/pa/humane/pa_resource.htm www.fbresarch.org/About/FAQ.htmonlineethics.org/reseth/mod/regan.htmlwww.stopanimaltests.comwww.peta.org/about/faq-viv.asp

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How do biological psychologists assess the structure and function of the nervous system?

• Biological psychologists use a variety of techniques to assess the structure and function of the nervous system.

1. Histology

Allows researchers to observe the structure, organization, and connections of individual nerve cells.

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Nerve tissue is “fixed” by freezing it or treating it with formalin.

Once fixed, the tissue is cut into slices 10-80 micrometers thick, mounted onto glass slides, stained, and examined under a microscope.

A number of stains are available. Examples:

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Golgi stain

Nissl stain

Myelin stain

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2. Autopsy

Allows researchers to examine nervous system structures that are too difficult to access using alternative techniques.

Involves examination of the body after death.

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Research Methods

1. What types of research methods do biological psychologists use? (continued)

2. What ethical considerations do biological psychologists face?

3. How do biological psychologists assess the structure and function of the nervous system?